The present invention relates to a new form of Carex pensylvanica plant named ‘Straw Hat’. ‘Straw Hat’ is an open pollination seedling of an unnamed Carex pensylvanica, not patented, characterized larger florets giving the plant a showier floral display to be unique and stable. The new plant was selected as a by the inventor as part of an on going grass breeding program since 2009 at a wholesale perennial nursery in Hebron, Ill. in 2010. The selection of this plant was due to larger florets giving the plant a showier floral display. Asexual, vegetative division propagation has been the only means of reproduction. Propagation has taken place at a nursery in Hebron, Ill. since 2011. In 2011 we planted 60 plants in pots. To date these plants have remained uniform in height. The new Carex pensylvanica has shown to be stable and identical in reproduction to the parent after making over 3000 vegetative divisions from 2011 to 2015. No plants of Carex pensylvanica ‘Straw Hat’ have been sold in this country, or anywhere in the world, prior to the filing of this application, nor has any disclosure of the new plant been made prior to the filing of this application with the exception of that which was disclosed within one year of the filing of this application and was either derived directly or indirectly from the inventor.